Now they'll have a chance to keep their historic quest going in the playoffs, too.
With the Triplets in sync and the defense producing another physically dominant performance, Tennessee never had a chance as the Colts rolled to a 35-3 victory to clinch a playoff spot and remain the NFL's only unbeaten team.
The Colts are the fifth team in league history to go 12-0, but must wait until next week at Jacksonville for a chance to wrap up their third straight AFC South title and first-round bye in the playoffs.
If the past few games are any indication, that's only a matter of time.
Indianapolis has won seven of its last nine by at least 17 points, averaging more than 35 points. The Colts even routed Tennessee on a day Manning threw only 17 passes, the second-fewest of his NFL career. He threw two passes in last year's season finale at Denver.
But the latest victory epitomized how Indy continues to win -- by overcoming anything opponents try.
The Titans (3-9) wanted to play keep-away. It didn't work.
Manning completed 13 of 17 passes for 187 yards and three touchdowns, giving him a near-perfect passer-rating of 151.2 and extending his NFL record to eight straight seasons with at least 25 TD passes.
Edgerrin James carried 28 times for 107 yards, becoming the third-fastest player in league history to top 9,000 yards. In 93 games, James has rushed for 9,067 yards. Eric Dickerson did it in 82 games; Jim Brown did it in 88.
Marvin Harrison caught four passes for 61 yards and his first reception, a 36-yarder on the Colts' opening drive, made Harrison the 12th player in league history to top 12,000 yards receiving. His 10-yard TD catch on the Colts' opening possession was the 92nd between Manning and Harrison, also extending that duo's NFL record.
If anyone thought Indy would have a letdown after an emotional victory on Monday Night Football against Pittsburgh, the Colts' answer was resounding: Not a chance.
They limited the Titans to 40 yards rushing, sacked Steve McNair twice and Billy Volek twice and even knocked McNair out for four plays in the third quarter with a bruised right shin.
"I'm very proud of this team, coming back after Monday night and playing like that, a complete game," coach Tony Dungy said. "We had that focus, we wanted to get in the playoffs."
A botched trick play to Adam "Pacman" Jones knocked the Titans out of field goal range and set up the Colts second score. Fisher gambled by going on fourth down routinely, failing four of five times, and in the waning moments when the Titans were trying to salvage a score, the Colts stopped them at the goal line.
It was that kind of day.
McNair was 22 of 33 for 220 yards, and fumbled when Dwight Freeney sacked him in the fourth quarter. Larry Tripplett grabbed the ball out of the air and went 60 yards for a touchdown.
"If we had played the perfect game, we could have won," said McNair, the NFL's former co-MVP.
Tennessee's only score came on Bironas' 24-yard field goal with 29 seconds left in the half.
"I know how hard it is to win nine games, 10 games, 11 games," Manning said. "To win 12 games is extremely hard, but to win 12 in a row ... You don't have time to pat yourself on the back as a team."
Notes: Dungy won his 100th regular-season game. ... The Colts extended their franchise record home winning streak to 11 and have now won 20 of their last 21 regular-season games. ... Kyle Vanden Bosch, who came into the game second in the NFL in sacks, had two wiped out by Tennessee penalties.